3x-ui-agent/internal/sub/controller.go

package sub

import (
	"bytes"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io/fs"
	"net/http"
	"os"
	"strings"
	"unicode"

	"github.com/gin-gonic/gin"

	"github.com/mhsanaei/3x-ui/v3/internal/logger"
	"github.com/mhsanaei/3x-ui/v3/internal/web/service"
)

// writeSubError translates a service-layer result into an HTTP response.
// A nil error with no rows means the subId doesn't match anything (deleted
// client, never-existed id) and becomes 404. A real error becomes 500. No
// body — VPN clients only look at the status.
func writeSubError(c *gin.Context, err error) {
	if err == nil {
		c.Status(http.StatusNotFound)
		return
	}
	c.Status(http.StatusInternalServerError)
}

// SUBController handles HTTP requests for subscription links.
type SUBController struct {
	subTitle        string
	subSupportUrl   string
	subProfileUrl   string
	subAnnounce     string
	subHideSettings bool

	subPath        string
	subEncrypt     bool
	updateInterval string

	subService     *SubService
	clientService  service.ClientService
	settingService service.SettingService
}

type subControllerConfig struct {
	subPath string

	subEncrypt     bool
	remarkTemplate string
	updateInterval string

	subTitle        string
	subSupportURL   string
	subProfileURL   string
	subAnnounce     string
	subHideSettings bool
}

type SUBControllerOption func(*subControllerConfig)

func WithSUBPath(value string) SUBControllerOption {
	return func(config *subControllerConfig) { config.subPath = value }
}

func WithSUBEncryption(value bool) SUBControllerOption {
	return func(config *subControllerConfig) { config.subEncrypt = value }
}

func WithSUBRemarkTemplate(value string) SUBControllerOption {
	return func(config *subControllerConfig) { config.remarkTemplate = value }
}

func WithSUBUpdateInterval(value string) SUBControllerOption {
	return func(config *subControllerConfig) { config.updateInterval = value }
}

func WithSUBTitle(value string) SUBControllerOption {
	return func(config *subControllerConfig) { config.subTitle = value }
}

func WithSUBSupportURL(value string) SUBControllerOption {
	return func(config *subControllerConfig) { config.subSupportURL = value }
}

func WithSUBProfileURL(value string) SUBControllerOption {
	return func(config *subControllerConfig) { config.subProfileURL = value }
}

func WithSUBAnnounce(value string) SUBControllerOption {
	return func(config *subControllerConfig) { config.subAnnounce = value }
}

func WithSUBHideSettings(value bool) SUBControllerOption {
	return func(config *subControllerConfig) { config.subHideSettings = value }
}

func defaultSUBControllerConfig() subControllerConfig {
	return subControllerConfig{
		subPath:        "/sub/",
		subEncrypt:     true,
		remarkTemplate: service.DefaultRemarkTemplate,
		updateInterval: "12",
	}
}

// NewSUBController creates a new subscription controller with the given configuration.
func NewSUBController(g *gin.RouterGroup, options ...SUBControllerOption) *SUBController {
	config := defaultSUBControllerConfig()
	for _, option := range options {
		option(&config)
	}

	sub := NewSubService(config.remarkTemplate)
	a := &SUBController{
		subTitle:        config.subTitle,
		subSupportUrl:   config.subSupportURL,
		subProfileUrl:   config.subProfileURL,
		subAnnounce:     config.subAnnounce,
		subHideSettings: config.subHideSettings,

		subPath:        config.subPath,
		subEncrypt:     config.subEncrypt,
		updateInterval: config.updateInterval,

		subService: sub,
	}
	a.initRouter(g)
	return a
}

// initRouter registers HTTP routes for subscription links on the provided
// router group.
func (a *SUBController) initRouter(g *gin.RouterGroup) {
	gLink := g.Group(a.subPath)
	gLink.GET(":subid", a.subs)
	gLink.HEAD(":subid", a.subs)
}

// maybeServeSubPage renders the HTML info page when the request comes from a
// browser (Accept: text/html) or explicitly asks for it (?html=1 or ?view=html).
// It reports whether the request was handled. The remark template's per-client
// info is for the content a client app imports — the raw subscription body. A
// browser viewing the HTML info page gets clean, name-only remarks (usage is
// shown in the page summary).
func (a *SUBController) maybeServeSubPage(c *gin.Context) bool {
	accept := c.GetHeader("Accept")
	wantsHTML := strings.Contains(strings.ToLower(accept), "text/html") || c.Query("html") == "1" || strings.EqualFold(c.Query("view"), "html")
	if !wantsHTML {
		return false
	}
	page, ok := a.buildSubPageData(c)
	if !ok {
		return true
	}
	a.serveSubPage(c, page.BasePath, page)
	return true
}

func (a *SUBController) maybeServeSubInfo(c *gin.Context) bool {
	if !strings.EqualFold(c.Query("format"), "info") {
		return false
	}
	page, ok := a.buildSubPageData(c)
	if !ok {
		return true
	}
	info := a.subPageContext(page)
	delete(info, "links")
	info["emails"] = dedupeEmails(page.Emails)
	setNoCacheHeaders(c)
	c.JSON(http.StatusOK, info)
	return true
}

func (a *SUBController) buildSubPageData(c *gin.Context) (PageData, bool) {
	subId := c.Param("subid")
	_, host, _, hostHeader := a.subService.ResolveRequest(c)
	subReq := a.subService.ForRequest(host)
	subReq.subscriptionBody = false
	subs, emails, lastOnline, traffic, err := subReq.getSubs(subId)
	if err != nil || len(subs) == 0 {
		writeSubError(c, err)
		return PageData{}, false
	}
	subURL := subReq.BuildURLs(a.subPath, subId)
	basePath, exists := c.Get("base_path")
	if !exists {
		basePath = "/"
	}
	basePathStr := basePath.(string)
	metadata := a.metadataForSubRequest(func() *SubService { return subReq }, subId, "")
	page := subReq.BuildPageData(subId, hostHeader, traffic, lastOnline, subs, emails, subURL, basePathStr, metadata.Title, metadata.SupportURL)
	page.SubAnnounce = metadata.Announce
	return page, true
}

func dedupeEmails(emails []string) []string {
	out := make([]string, 0, len(emails))
	seen := make(map[string]struct{}, len(emails))
	for _, email := range emails {
		if email == "" {
			continue
		}
		if _, dup := seen[email]; dup {
			continue
		}
		seen[email] = struct{}{}
		out = append(out, email)
	}
	return out
}

// subs handles HTTP requests for subscription links, returning either HTML page or base64-encoded subscription data.
func (a *SUBController) subs(c *gin.Context) {
	userAgent := c.GetHeader("User-Agent")
	if a.maybeServeSubInfo(c) {
		logSubscriptionRoute(userAgent, "info")
		return
	}
	if a.maybeServeSubPage(c) {
		logSubscriptionRoute(userAgent, "html")
		return
	}
	if !a.enforceHwid(c) {
		return
	}
	logSubscriptionRoute(userAgent, "raw")
	subId := c.Param("subid")
	scheme, host, hostWithPort, _ := a.subService.ResolveRequest(c)
	subReq := a.subService.ForRequest(host)
	subReq.subscriptionBody = true
	subs, _, _, traffic, err := subReq.getSubs(subId)
	if err != nil || len(subs) == 0 {
		writeSubError(c, err)
	} else {
		var result strings.Builder
		for _, sub := range subs {
			result.WriteString(sub)
			result.WriteString("\n")
		}

		// Add headers
		header := fmt.Sprintf("upload=%d; download=%d; total=%d; expire=%d", traffic.Up, traffic.Down, traffic.Total, traffic.ExpiryTime/1000)
		profileURL := fmt.Sprintf("%s://%s%s", scheme, hostWithPort, c.Request.RequestURI)
		metadata := a.metadataForSubRequest(func() *SubService { return subReq }, subId, profileURL)
		a.ApplyCommonHeaders(c, header, a.updateInterval, metadata.Title, metadata.SupportURL, metadata.ProfileURL, metadata.Announce, a.subHideSettings)

		if a.subEncrypt {
			c.String(200, base64.StdEncoding.EncodeToString([]byte(result.String())))
		} else {
			c.String(200, result.String())
		}
		a.recordSubscriptionFetch(c)
	}
}

func (a *SUBController) recordSubscriptionFetch(c *gin.Context) {
	if c.Request == nil || c.Request.Method != http.MethodGet || c.Writer.Status() != http.StatusOK {
		return
	}
	if err := a.subService.RecordSubscriptionFetch(c.Param("subid")); err != nil {
		logger.Warning("Failed to record subscription fetch:", err)
	}
}

func logSubscriptionRoute(userAgent, branch string) {
	logger.Debugf("Subscription request routed: branch=%s user_agent=%q", branch, sanitizeUserAgentForLog(userAgent))
}

func sanitizeUserAgentForLog(userAgent string) string {
	clean := strings.Map(func(r rune) rune {
		if unicode.IsControl(r) {
			return ' '
		}
		return r
	}, userAgent)
	runes := []rune(clean)
	if len(runes) > 512 {
		return string(runes[:512])
	}
	return clean
}

// serveSubPage renders internal/web/dist/subpage.html for the current subscription
// request. The Vite-built SPA reads window.__SUB_PAGE_DATA__ on mount —
// we inject that here, along with window.X_UI_BASE_PATH so the
// page's static asset references resolve correctly when the panel runs
// behind a URL prefix.
func (a *SUBController) serveSubPage(c *gin.Context, basePath string, page PageData) {
	var body []byte
	if diskBody, diskErr := os.ReadFile("internal/web/dist/subpage.html"); diskErr == nil {
		body = diskBody
	} else {
		readBody, err := fs.ReadFile(distFS, "dist/subpage.html")
		if err != nil {
			c.String(http.StatusInternalServerError, "missing embedded subpage")
			return
		}
		body = readBody
	}

	// Vite emits absolute asset URLs (`/assets/...`); when the panel is
	// installed under a custom URL prefix, rewrite them so the bundle
	// loads from `<basePath>assets/...` where the static handler is
	// actually mounted.
	if basePath != "/" && basePath != "" {
		body = bytes.ReplaceAll(body, []byte(`src="/assets/`), []byte(`src="`+basePath+`assets/`))
		body = bytes.ReplaceAll(body, []byte(`href="/assets/`), []byte(`href="`+basePath+`assets/`))
	}

	subData := a.subPageContext(page)

	subDataJSON, err := json.Marshal(subData)
	if err != nil {
		subDataJSON = []byte("{}")
	}

	// Defense-in-depth string-escape for the basePath embed — admin-
	// controlled but cheap to harden.
	jsEscape := strings.NewReplacer(
		`\`, `\\`,
		`"`, `\"`,
		"\n", `\n`,
		"\r", `\r`,
		"<", `<`,
		">", `>`,
		"&", `&`,
	)
	escapedBase := jsEscape.Replace(basePath)

	inject := []byte(`<script>window.X_UI_BASE_PATH="` + escapedBase + `";` +
		`window.__SUB_PAGE_DATA__=` + string(subDataJSON) + `;</script></head>`)
	out := bytes.Replace(body, []byte("</head>"), inject, 1)

	setNoCacheHeaders(c)
	c.Data(http.StatusOK, "text/html; charset=utf-8", out)
}

// subPageContext builds the shared view-model map: the template context for
// custom sub themes, the window.__SUB_PAGE_DATA__ payload the SPA reads, and
// (without links) the ?format=info JSON body. The panel's "Calendar Type"
// setting decides whether dates render Gregorian or Jalali — surfaced here so
// consumers match the rest of the panel without a round-trip.
func (a *SUBController) subPageContext(page PageData) map[string]any {
	datepicker, _ := a.settingService.GetDatepicker()
	if datepicker == "" {
		datepicker = "gregorian"
	}

	return map[string]any{
		"sId":           page.SId,
		"enabled":       page.Enabled,
		"isOnline":      page.IsOnline,
		"download":      page.Download,
		"upload":        page.Upload,
		"total":         page.Total,
		"used":          page.Used,
		"remained":      page.Remained,
		"expire":        page.Expire,
		"lastOnline":    page.LastOnline,
		"downloadByte":  page.DownloadByte,
		"uploadByte":    page.UploadByte,
		"totalByte":     page.TotalByte,
		"subUrl":        page.SubUrl,
		"subTitle":      page.SubTitle,
		"subSupportUrl": page.SubSupportUrl,
		"links":         page.Result,
		"emails":        page.Emails,
		"datepicker":    datepicker,
		"announce":      page.SubAnnounce,
	}
}

func (a *SUBController) enforceHwid(c *gin.Context) bool {
	result, err := a.clientService.EnforceHwidForSubID(c.Param("subid"), service.HwidRequest{
		Hwid:        c.GetHeader("X-HWID"),
		UserAgent:   c.GetHeader("User-Agent"),
		DeviceOS:    c.GetHeader("X-Device-OS"),
		OsVersion:   c.GetHeader("X-Ver-OS"),
		DeviceModel: c.GetHeader("X-Device-Model"),
	})
	if err != nil {
		writeSubError(c, err)
		return false
	}
	applyHwidHeaders(c, result)
	if !result.Allowed {
		c.Status(http.StatusNotFound)
		return false
	}
	return true
}

func applyHwidHeaders(c *gin.Context, result service.HwidGateResult) {
	if result.Active {
		c.Header("X-Hwid-Active", "true")
	}
	if result.NotSupported {
		c.Header("X-Hwid-Not-Supported", "true")
	}
	if result.LimitReached {
		c.Header("X-Hwid-Limit", "true")
	}
	if result.MaxDevicesReached {
		c.Header("X-Hwid-Max-Devices-Reached", "true")
	}
}

// setNoCacheHeaders marks a subscription page response as non-cacheable so VPN
// clients and browsers always fetch fresh traffic/expiry data.
func setNoCacheHeaders(c *gin.Context) {
	c.Header("Cache-Control", "no-cache, no-store, must-revalidate")
	c.Header("Pragma", "no-cache")
	c.Header("Expires", "0")
}

// ApplyCommonHeaders sets common HTTP headers for subscription responses including user info, update interval, and profile title.
func (a *SUBController) ApplyCommonHeaders(
	c *gin.Context,
	header,
	updateInterval,
	profileTitle string,
	profileSupportUrl string,
	profileUrl string,
	profileAnnounce string,
	profileHideSettings bool,
) {
	c.Writer.Header().Set("Subscription-Userinfo", header)
	c.Writer.Header().Set("Profile-Update-Interval", updateInterval)

	// Basics
	if profileTitle != "" {
		c.Writer.Header().Set("Profile-Title", "base64:"+base64.StdEncoding.EncodeToString([]byte(profileTitle)))
	}
	if profileSupportUrl != "" {
		c.Writer.Header().Set("Support-Url", profileSupportUrl)
	}
	if profileUrl != "" {
		c.Writer.Header().Set("Profile-Web-Page-Url", profileUrl)
	}
	if profileAnnounce != "" {
		c.Writer.Header().Set("Announce", "base64:"+base64.StdEncoding.EncodeToString([]byte(profileAnnounce)))
	}

	if profileHideSettings {
		c.Writer.Header().Set("Hide-Settings", "1")
	}
}